In the technical fields of petroleum, chemical industry, metallurgy, electricity, nuclear power or the like, the main valve of high-temperature, high-pressure and large-flow shut-off device is generally a check valve, a gate valve, a ball valve and etc., which have their respective merits but are defective in sealing, vibration, noise, erosion, seismic resistance. At the same time, due to great vertical height and complex structure, the valve body cannot be mounted at any angle and has poor economical interest due to high cost and energy consumption; also the valve body has poor reliability and increased longitudinal stacking height.
Current drive systems are mainly categorized into two groups:
1. system medium drive (i.e. passive controlled) which is simple, energy-saving but whose on-off quality is affected by fluctuation of system pressure and on-off time cannot be adjusted;
2. peripherals power source drive which can not only be normally activated and deactivated and also shut off in emergency, whose on-off time is adjustable without being affected by fluctuation of system pressure, and which has relative higher costs due to addition of related devices.
The drive system of current valve on-off adjusting device is dull and has poor drive stability and reliability, and on-off speed and flow rate of the valve cannot be adjusted.